Starting with Windows 10 Insider build 14926, you can now send and receive SMS text messages from the updated Skype Preview app on your Windows 10 PC and Windows 10 Mobile phone.
The SMS relay feature is part of this update, and allows users to send and receive SMS and MMS messages directly from a Windows 10 PC when Skype on your Windows 10 Mobile is set as the default messaging app. No need to reach for your phone, you can view new messages as they arrive and respond to messages from your computer. Send and receive texts, group messages, and photos all in one app with a single view of your SMS and Skype conversations.
This tutorial will show you how to enable or disable SMS sync in the Skype Preview app for your Windows 10 PC and Windows 10 Mobile phone to send SMS.